Improvement in hot-air furnaces



UNITED STATES PATENT OFFICE.

HENRY ARDEN, OF CINCINNATI, OHIO.

IMPROVEMENT IN HOT-AIR FURNAES.

Specification forming part of Letters Patent No. 74,270, dated February 11, 1868.

To all whom 'it may concern:

Be it known that I, HENRY ARDEN, of Cincinnati, Hamilton county, Ohio, have invented a new and useful Hot-Air Furnace 5 and I hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawing, making part of this specification.

My furnace is designed to secure the most useful and economical results in an air-heating furnace, by the slow combustion of aA considerable bulk of fuel distributed over a large area of radiating-surface.

In the accompanying drawing, a furnace embodying my invention is shown, 'partly in elevation and partly in vertical section.

A is the base-wall, inclosing an ash-pit, B, which pit is traversed by a series of bars, G, that support a grate formedof separate bars, D. The sides ofthe ash-pit are sloped inward at their upper portion, so as to collect the ashes into a central trench of small dimensions, accessible by a door, P, of correspondi'ng size. Rising vertically from and supported by the base A is the exterior wall or shell E, and concentrically within said shell a fire-ch amber, F, which said shell and fire-chamber inclose between them an annular space, Gr, whose lower part has inlets H for cold air, and whose upper part has outlets I for air that has been heated by contact with the exterior surface of the fire-chamber.

H1 is an annular deecting sheet or plate, extending horizontally inward from the shell, just above the air-inlets H, and operating to force the cold air against the external sides of the nre-chamber, so as to take up all the available heat thereof, and to prevent the direct escape of the cold air into the warm-air pipes. The plate H is also useful by producing an equal circulation or current of air on all sides.

Supported on columns J, or otherwise, in the center of the'furnace, is a pier, K, preferably in the form of a truncated cone, as represented, and which, imparting an annular form to the fire-chamber, affords a large external radiating-surface for a given capacity of furnace. The fuel is introduced through openings L near the top of the fire-chamber, said openings having sloping spouts or throats L, to conduct the fuel across the annular space ing. These doors enable the reman to shake down the ashes without materially opening the furnace.

O is a small registered draft-hole. The heated air is conducted wherever desired by` pipes fitting on the necks of the outlets I.

One or more draft-tubes, Q, may be provided to increase the combustion. R is apipe to contain water to be heated.

It will be seen that the pier K serves to displace the amount of coal which would other# wise uselessly occupy the center of the fur-` nace. It will also be seen that my furnace is essentially air-tight and is adapted for the slow and protracted combustion of a large' amount of fuel.

I claim herein as new'and of my inventionl. The provision, in an air-heating furnace, of the annular lire-chamber F, constructed as described, and provided with fuel-feeding passages L L', substantially' as set forth.

2. The ashpit B, with sloping sides and central trench, formed and arranged as de scribed.

3. The arrangement of the air-'heating furnace A B C D E, fire-chamber F, and`in1perforate central pier K, forthe purpose explained.

4. In combination with the foregoing, the annular deflecting-plate H', with the air-inlet H and hot-air chamber G, as ,and for the purpose set forth. f"

5. The doors N N, formed and arranged as shown, in combination with the grate D and imperforate -pier K, annular fire-chamber F, and draft-tubes Q, as set forth.

In testimony of which invention I hereunto set my hand.

HENRY ARDEN.

Witnesses GEO. H. KNIGHT, J AMES H. LAYMAN. 

